Sliver condenser for drawing frames

ABSTRACT

A SILVER COMPRESSOR IN THE FORM OF A TRUMPET HAVING AN INSERT ENCASED IN A LOWER PORTION CONSTRUCTED OF MATERIAL HAVING A HIGH WEAR RESISTANCE TO SILVER PASSING THERETHROUGH. THE MAIN BODY OF SAID TRUMPET IS CONSTRUCTED OF MATERIAL CAPABLE OF DISSIPATING HEAT READILY.   THE TRUMPET IS SUPPORTED ON BEARINGS WHICH RIDE ON THE CALENDER ROLLS FOR MINIMIZING WEAR DUE TO THE FRICTIONAL CONTACT THEREWITH.

Feb. 16, 1971 G. :5. FORNES SLIVER CONDENSER FOR DRAWING FRAMES Filed Oct. 18, 1968 INVENTOR. GASTON G. FORNES ATTORNE 5.

United States Patent 3,562,863 SLIVER CONDENSER FOR DRAWING FRAMES Gaston G. Fornes, Charlottesville, Va., assignor to Cometsa Corporation, Charlotte, N.C., a corporation of North Carolina Filed Oct. 18, 1968, Ser. No. 768,841 Int. Cl. D01h 5/72 US. Cl. 19-150 2 Claims ABSTRACT OF THE DISCLOSURE A sliver compressor in the form of a trumpet having an insert encased in a lower portion constructed of material having a high wear resistance to sliver passing therethrough. The main body of said trumpet is constructed of material capable of dissipating heat readily. The trumpet is supported on bearings which ride on the calender rolls for minimizing wear due to the frictional contact therewith.

This invention relates to drawing frames and the like, and particularly to a novel structure for delivering sliver to the calender rolls.

In drawing frames normally used in spinning, the sliver, on leaving the drafting rolls passes through a trumpet placed on a plate and is carried to a pair of calender rolls after which the sliver is taken up in a revolving can in which it is laid out. For best operation of this step, it has been found advantageous to introduce the sliver in the calender rolls at substantially the very point of tangency of the latter, which is the point of contact of these rolls. In actual practice this is difficult since the trumpet must be placed so that its lower orifice is above the point of tangency of the calender rolls as otherwise, due to the thickness of the walls of this trumpet, it would be in contact with the calender rolls and would score them.

Thus, normally, there is a certain length of sliver free between the lower orifice of the trumpet and the rolls, and if the orifice is wide, the sliver opens out or expands in this area, with a subsequent reduction of the amount of sliver that can be contained in the take-up can. This is a pronounced disadvantage in modern high production spinning plants. On the other hand, if the trumpet orifice is narrow, there is a degree of friction applied to the sliver which tends to hold the sliver in the trumpet and causes the sliver to be pulled out by the calender rolls which are pulling it downward, thereby causing irregularity in the yarn ultimately spun.

Moreover, with this usual arrangement, the trumpet has changes in position due to the normal vibration of the machine which is also a disadvantage since it is desirable for the axis of the trumpet to be maintained at substantially a tangential angle with respect to both calender rolls at a point of tangency of the rolls, and this requires periodic checking of the positioning of the trumpet.

The present invention is concerned with certain improvements in drawing frames, by which the previously mentioned disadvantages are avoided, and which also provide other important advantages, since without danger of scoring the rolls and without having to regulate the position of the trumpet, they allow carrying the sliver virtually to the precise point of tangency of the calender rolls without producing any change in the cross-section of the sliver, and this cross-section can be fixed by means of a strong compressive force exerted thereupon by the calender rolls.

The improvement includes a trumpet having a main body portion of a substantially prismatic shape and an insert encased in a lower portion of said main body portion. The main body portion has two lower concave cylindrical faces with a radius corresponding to that of the calender rolls which converge at a common lower edge and which has a conical perforation, with two tapers, whose base opens out in the top opposite the said edge, with a relatively large taper and having in the lower half a cone of relatively reduced taper whose vertex coincides with the center of the aforementioned edge, which is formed by the convergence of the cylindrical faces. The lower portion of the perforation which includes the lower half of the cone that terminates in the reduced taper is defined by and extends through the insert as shown in the drawing.

The insert is constructed of any suitable material, such as ceramic, which has a high wear resistance to the sliver passing through the trumpet. In order to dissipate the heat generated by the sliver passing through the restricting passageway in the insert, the main body of the trumpet is constructed of any suitable material which dissipates heat readily, such as aluminum.

Bearings are carried by the main body of the trumpet or element and extend slightly below the cylindrical faces for supporting the element on the calender rolls for minimizing the frictional contact between the element and the calender rolls.

The orifice of the trumpet which is in the shape of a cone is situated virtually at precisely the line of tangency of the calender rolls. The upper face of the trumpet is positioned at substantially the same level as the upper face of the carrying plate, resting or positioned loosely in an opening in this plate of such size as to correspond in shape.

In this way, the trumpet has a certain amount of freedom of movement which allows the automatic centering of the exit orifice of the trumpet, eliminating the need for adjusting the usual trumpet above the carrying plate and eliminating any danger of scoring the rolls. At the same time, the sliver is delivered to the calender rolls at virtually the precise tangential point of the calender rolls. This means that in this way the sliver enters the calender rolls with the same reduced cross-section that it has on exiting from the trumpet orifice, without having any opportunity to open out or expand. This provides the important advantage that, if there is exerted on the calender rolls a reciprocal pressure sufficiently large, the cross-section of the sliver becomes fixed permanently due to the pressure to which it is subjected, and thereby achieving a much greater capacity of the take-up can over the usual. The uniformity or consistency of the sliver is also increased, favoring its subsequent handling and avoiding slack twist in subsequent operations, all of which makes for greater regularity in the yarn subsequently obtained.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing forming a part thereof, wherein an example of the invention is shown and wherein:

FIG. 1 is a schematic longitudinal cross-sectional view, illustrating the sliver as it leaves the drafting elements of a drawing frame and the like, showing how it is carried to the point of tangency of the calender rolls in accordance with the present invention,

FIG. 2 is an enlarged perspective view of a device constructed in accordance with the present invention, and

FIG. 3 is a front elevation illustrating the rear section of such device, with the front section removed, to show the interior of the assembled device and in particular an insert' carried in the lower portion.

As FIG. 1 illustrates, the sliver on leaving the last pair of rolls 11 of the drafting means passes over a plate 12 which has an opening 13 under which the calender rolls 14 are located for delivering the sliver 10' to the can (not shown).

Usually, the trumpet is mounted in the circular opening 13 with its exit orifice positioned a given distance above the rolls 14. However, it is preferable that the opening 13 be made slightly larger than the top of the trumpet and of a circular shape as to allow positioning of the trumpet with certain looseness, and so that the upper face may be at substantially the same level as the plate 12. The main body 15 is essentially prismatic in shape, being constructed of any suitable material which dissipates heat readily, such as aluminium with a black oxide finish, and has lower cylindrical faces 16 with a radius corresponding to that of the calender rolls 14, and which converge almost tangentially forming a lower edge 17.

An insert 18 is encased in the lower portion of the main body 15, and is constructed of any suitable material, such as ceramic, which has a high wear resistance. One suitable ceramic material is manufactured by American Lava Corporation of Chattanooga, Tenn., and is referred to as Alsimag.

Extending through the body 15 and the insert 18 is an internal recess in the general shape of a truncated cone as at 19, with a substantial taper, the base of which opens in the upper face of the body, and which has a lower second conical section 20 with a lesser taper and whose vertex coincides with the center of the lower edge 17, forming an orifice 21 of relatively small size.

:In actual practice, and in order to facilitate the cleaning of the inside of the trumpet without danger of damaging the exit orifice 21, particularly when the sliver is stuck in the trumpet, or breaks inside it, the main body 15 of the trumpet is made preferably in two halves 15 and 15" in a plane perpendicular to the lower edge 17. The halves are connected together by screws 22 which are housed in bores 23 in both halves or by other suitable means. As is best illustrated in FIGS. 1 and 3, the insert 18 is carried within a complementary recess in the lower portion of the main body 15.

Different size inserts 18 may be used when processing various sliver weights. The trumpet halves 15' and 15" can be separated for cleaning and replacing of the inserts as required. Therefore, a single trumpet body can serve for all the inserts provided for an entire range of sliver weights.

A set of three ball bearings 24 properly sealed and shielded keep the trumpet properly positioned on the smooth surface drawing rolls 14 acting somewhat as a three leg stool. These ball bearings 24 turn at low speeds (for ball bearings) and have very low friction, and can position the trumpet such that even the very hard insert 19 cannot damage the drawing rolls 14. The pair of opposed ball bearings 24 on the left, as shown in FIG. 1, are rotatably mounted on bolts 25 which extend into opposed sides of the halves 15 and 15". The ball bearing 24 on the right is carried on a shaft extending between the opposed halves 15 and 15" in a recess 27 provided to accommodate such. All of the ball bearings 24 extend slightly below the cylindrical faces 16 for supporting the trumpet on the calender rolls 14 to minimize the frictional contact therebetween.

Preferably, and to facilitate the movement of the sliver through the interior of the trumpet and to increase the effect of the reduction of the cross-section of the sliver, the upper conical perforation is made with convex taper 28 and the lower conical perforation 20 with a concave taper 29, and the two conical perforations being connected together in a smooth curve so that the inner surface of the trumpet progresses smoothly from the upper to the lower conical perforations and the lower perforation 20 is prolonged in a narrow cylindrical passage 30 terminating in the exit orifice 21. This body made in the way described includes a passageway having a double conical portion whose upper-half portion guides the sliver in the trumpet and reduces the section of the sliver, while the lower-half portion 20 with the prolongation 30 acts as a second section reducing portion for the sliver. As can be seen, a portion of the lower conical section 20 and the narrow passage 30 is included in the insert 18. The bearings 24 support the main body 15 on the calender rolls 14 so that the lower edge of the cylindrical faces 16 with the exit orifice 21 coincides almost exactly with the line of tangency of the rolls 14, and an upper fiat face of the body is below the plate 12 with the cylindrical top horizontal face 31 of the funnel or cone 18 extending through the opening '13 and terminating at the same level as the upper face of the carrying plate 12.

As can be seen, in this arrangement the sliver 10 is carried to the very point of tangency of the rolls 14 eliminating that section of the sliver which usually remains free between the exit orifice 21 of the usual trumpet and the nip or pressure point (point of tangency) of the calender rolls. This eliminates the expansion of the sliver and, also, any possibility of distension, but without any danger of scoring the surface of the rolls 14 due to the fact that the main body is supported on the ball bearings 24. The calender rolls 14 are preferably mounted on supporting elements connected together which are urged towards each other by tension created by appropriate means, such as springs (not shown) so that the tension is compensated by the mutual reaction of both rolls, without being transmitted to supporting elements on the machine. The sliver thus receives strong compression which fixes the cross-section of the sliver as it exits from the device.

Inserts 19 having different size passageways 30 can be used when processing various sliver weights, and in one particular embodiment the diameter of the passageway is three millimeters. Since the insert is made of hard ceramic material, such does not Wear readily as the sliver passes therethrough and is compressed by the narrow passage 30, and the heat generated by the frictional contact is dissipated by the main body 15 of the trumpet. By constructing the main body of aluminum bar stock with a very black oxide surface such provides excellent heat conductivity, as well as heat radiation from the trumpet. This helps to prevent high temperatures in the sliver, as well as helps reduce trumpet throat wear.

While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.

What is claimed is:

1. For use in drawing frames and the like having a plate for the sliver beyond the exit of the sliver from the drafting elements, and calender rolls which deliver the sliver to a can, the improvement including an element of essentially prismatic shape having a main body portion and an insert encased in a lower portion of said main body portion, said main body having an upper face, lateral concave cylindrical faces below said upper face with a radius corresponding to the calender rolls converging at virtually a tangential angle forming a lower edge, a passageway extending through said main body portion terminating in a narrow exit orifice extending through said insert, said insert being constructed of material having a high wear resistance to said sliver passing therethrough, ball bearing means carried by said element and in engagement with said calender rolls for support of said element thereon, and said main body of said prismatic shaped element being constructed of material capable of dissipating heat readily, whereby said insert resists frictional wear resulting from said sliver passing therethrough while said main body portion readily dissipates the frictional heat generated.

2. The structure as set forth in claim 1, wherein said insert is constructed of ceramic material and said main body of said prismatic shaped element is constructed of aluminum with a black oxide finish.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 609,753 10/1948 Great Britain 19157 786,528 11/1957 Great Britain 19288 222,775 10/1942 Switzerland 19157 DORSEY NEWTON, Primary Examiner US. Cl. X.R. 19288 

